Office



(No Model.)

B. ROESING. GUPE'LLING FURNACE.

Patented Ngv.

INVENTOR:

ATTORNEYS.

W 'l'N E8858 2 (work-lead, bullion, 820.) on ya firm metallic.

UNITED STATES PATENT CUPELLl NG-FURNACE.

SPECIFICATION forming part of Letters Patent No. 289,143, dated November 27, 1883.

Application filed July 13, 1883. (E0 model.) Patented in Germany September 2, 1882, No. 22.610. h

To all whom it may concern.-

- Be. it known that I, BERNHARD Ronsmc, of Friedrichshutte, Upper Silesia, Germany, have invented a new and Improved Cupelling' Furnace, of which the following is a full, clear, and exact description.

My improvements relate to apparatusused in the extraction of precious metals from base bullion, 8nd, by the method of cupellation.

The invention consists in cupelling the alloy cupel, which is supported on suitable bearings in such a manner that a rolling or sliding motion, of any desired extent to and fro may be imparted to it, so as to permit of a partial or total emptying of the contents of the cupel-hearthwithout, except in the latter case of complete discharge, disturbingthe normal position of the molten metal bath with' respect to the blast or the flame acting upon it, and without interrupting the process of cupellation. The products of oxidation (scum, litharge, 8:0.) are completely withdrawn from the cupel, absorption of the same to any degree whatever not being intended. For this rea son the usual test materials,such as bone-ash, cement, artificial mixtures of various earths, 830. are dispensed with, and an adequate metal (preferably iron, cast or wrought) substituted as working-bottom. However, to guard this non-refractory material against corrosion or oxidation, and to prevent overheating of the cupel, as well as to avoid too great a cooling ofi of .the molten lead through extraneous sources, (from under surface of cupel, &c.,) the cupel is covered with a lining of some refractory material, which will simultaneously resist both the chemical and mechanical influences of the products of cupellation.- .As a means against overheating, the cupel may, furthermore, be cooled by air or water, or both combined.

To permit of the removal of the intermediate (litharge, 8:0.) as well as of the final products of cupellation, (enriched lead or fine silver,) the cupel is provided with the usual outlet-thelitharge channel or gutter. This, consisting of a simple depression of the surface of the cupel, and being therefore rigid, does not allow of the customary deepening of the channel for the purpose of drawing off the litharge' in conformity to the gradual. sinking of the lead surface. Any such change of the level of the channel is, however, entirely, obviated by the perfect control over the elevation of the outlet which the peculiar tilting motion of the cupel furnishes, as this enables the operator not only to completely discharge the contents at any stage of the process, but also fords him an easy means to regulate the overflow 0f litharge with the greatest nicety, without the labor of cutting away test material, or, when subsequently introducing lead, (after charging,) to refill the cupel without thedifficult work of heightening thechannel. For these purposes it is but necessary to operate a simple mechanical contrivance, whose'great advantage, besides requiring but a slight de gree of bodily exertion, is that its manipulation does not withdraw the attention of the,

cupeller from a constant observation of the litharge-outlet.

With slight changes, not affecting the theory of its action or design, the cupel may be applied equally well to furnaces of the common English pattern, in vogue in England and this country, as to such 'of the'prevailing German pattern with removable hood or dome. The difference mainly lies in the manner of introducing the cupel, which in the first case would be from below, and in the second from above. A

Another distinction of inferior importance would be constituted by the mode of securing the bearings on which the cupel moves. The existing English furnace would most conveniently be suited by mounting it on a firm carriage or truck, with mechanism to raise the body of bearings and cupel into proper position after the truck has been set in place between fire-bridge wall and flue-wall of the furnace. The existing German cupellinghearth, on the other hand, would suggest firm connection of the bearings with the foundation or furnace-body.

In the accompanying drawings, forming part of this specification, in which similar letters of reference indicate corresponding parts inall the figures, the cupel is shown as applied to a furnace of independent design, but somewhat resembling the German Treibherd in external shape, as well as by the presence of a 2 v 2s9,14a

hood and the absence of a culvert and stack. All accessory details-such as hood, particu-.. lars of fire-place, fiue, &c.-however, have been omitted for the sake of clearness,

Figure 1 represents a cross-section through furnace with cupel in normal position, on that vertical meridian plane of the latter which is parallel to the fire-bridge, this plane also containing the greatest are described by any point of the cupel-surface during motion. Fig. 2 is a cross-section on the meridian plane at right angles to the above and parallel to the furnace-- front; 3, a horizontal cross-section on the level of the tuyeres, (except the opening 0,) the cupel being omitted and the supportingbeams shown in dotted lines. Fig. 4 is a per spective view of the cupel, and Figs. 5 and 6 are detail views.

O'is the cupel; A, its center of curvature; y, the fire-place; x, the fire-bridge; a, the opening above the fire-bridge connecting fireplace and cupelling-furnace proper; 0, the charginghole (German furnace) or flue leading to stack, (English furnace.) m m are the tuyere-holes.

- The cupel O, of which Fig. 4 gives a perspective view, consists of a concave-convex metal shell (cast or wrought iron) placed with concavity upward, and fastened to a rectangular system of I-beams, a 71 as shownin Fig.

g is the litharge-channel, consisting of a gut ter-like depression in the surface of O, and ex tending some distance inward from the cirdownward.

cugnference. Its middle line is contained in the meridian plane of tilting, and its inclina-. tion (or length) is so chosen that when the cupel is tilted back to near its highest the channel is either horizontal or already dipping The lining of the cupel is indieated by Z Z, Figs.- 1 and 2.

Of the group of I-beams forming the framework of the cupel, the greater number, a, lie parallel to the direction of tilting, and are somewhat higher than beams h, which are disposed at right angles to them. The first, again, when the cupel is in motion, move on a system of twenty-four trundles, r, whose axes are bound to a firm support of I-beams, 25, parallel in curvature, respectively, to the beams of the cupel. In the design presented, these supporting-beams t are themselves borne by two uprights each, sunk in the foundation of the furnace.

Figs. 5 and 6 represent the arrangement of trundle and supporting I-beani. It is clear that the I-beam a of the cupel may without hinderance be made to roll over in.

The mechanism for tilting is shown in Fig. 1.

The cross-beams h carry a cogged segment, 8,

in gearing with the cog-wheel 2'. The center line of s and the plane of z are contained in the meridian plane of motion. The shaft 10, properly supported, upon which 2 is keyed, extends to the outside of the furnace-body,

. from where motive force may be imparted to it, directly or indirectly, by means of any contrivance preferred, such as lever, crank, hydraulic jack, &c. As shown, power is to be which, as is indicated in Figs. 2 and 3, transmits the motion to w by a secondary shaft, '0, r

at right angles to the first, an endless screwgearing (p and q in Figs. 2 and 3) transferring the power. This relation ofparts expressed requires the mechanism to be operated by an assistant of the cupeller, as the crank-wheel a has been placed out of reach of the latter when standing in front of the litharge-channel. A slight alteration, however, would remove this objection, in case the cupeller were required to perform the tilting himself.

It is clear that under circumstances such, for instance, as the adaptation of the cupel to the existing form of English furnace it may become advisable to make use of a device for moving pinion z of an entirely different design from the one here given.

Now, since the supporting-beams t and their parallel beams belonging to the frame of the cupel are so placed that vertical planes passed through their lines of curvature cut cross-sec tions parallel to these lines in the surface of the cupel, and a similar relation obtains with regard to vertical planes passed through curves connecting corresponding points of the trundles r, it is evident that the cupel is constrainedto move about its center of curvature A, whereas the normal position of the molten bath of metal at the lowest point of the cavity of the cupel is not altered with regard to any fixed point of the furnace (tuyeres, fire-place) during this motion. In other words, while the cupel is withdrawn from beneath the molten metal, the mass of "the latter remains in the same absolute position, being neither raised nor lowered, nor drawn to any side. Rapid movement might, of course, causesome commotion in the liquid bodythrough friction; but for such motion there will he usually no occasion during cupel lation. The material of the lining must be an appropriate mixture of a chemiealconstitution similar to that of the working-bottoms of the German process of cupellation, or the various mixtures of earths,&c., that have more or less in this country superseded the use of boneash in the English process; yet the'material must differ in this important respect, that it must be but a poor conductor of heat, and must, furthermore, be so dense as to absorb but the very smallest amount of litharge, or none at all, as otherwise the conducting-power is again increased to disadvantage.

Toward the end of cupellation, or,'as the case may be, during the entire process, it may be advisable to make use of hot blast to counteract loss of heat through radiation or from other sources.

lows:

First. It obviates'loss of time and necessity for skilled labor for frequent preparing of a test, also skilled labor for deepening or patching up the litharge-channel. Renewal of lin- The advantages of this I cupel are as fol- I ing-i. a, test materiah-being but seldom necessary, the cupel may remain in use uninterruptedly for an indefinite time,as compared with those now in use, especially the English one of bone-ash.

Second. Itpermits a more perfect control and an easier and nicer adjustment of the overflow of lithargethan by deepening the channel Third. It is more convenient, for a similar.

tirely at any stage of the process.

Fifth. All operations connected withthe" moving of the cupel may be performed without drawing the attention of the cupeller from the observation of the litharge-channel, and without requiring him to leave his position in front of the cupel.

Sixth. lhe motion'of the cupel in no wise disturbs the absolute position of the molten bath of metal, (except; when emptying cupel of contents.) y

I do not claim any peculiar design of furnaee, the cupel being adaptableto all existent shapes without ohaugein principle.

. I am aware that the typical English test has been so modified as to discard the custom of tapping litharge and fine silver frombelow with drills by closing the test-ring perfectly on its under side by an iron test-plate which serves as a support for the cupel of bonensh, Portland cement, or other material, in- 40 stead of the former transverse bars. Being thus but part of the test, and bearing no immediate relation to the absorptive cupel resting upon it, this iron test-plate, however, differs materially from the iron shell protected merely by a comparatively thin nonabsorptive lining against corrosion, 850., which characterizes my invention in serving as cupel proper. Theriron shell constitutes the working-bottom itself, not a test bearing a cupel of other material.-

I am aware or tipping the test and cupel have been made use of in this country partly in connection with the above -mentioned test plate, and chiefly for the purpose of castingby discharging the refined silver from the cupel directly into molds. The mechanism for this operation is, however, comparatively simple, asthe motion is a crude one, and consists in bringing the cupel to a downward slant, so as to empty it, either by raising its back or letting the front drop.

The motion of my cupel, being of an entirely difi'erent character, and having no influence upon the position of the molten metal one way or the other, may be made use of for the three purposes of partially letting off the contents, refilling, or totally emptying the cupel at any moment without danger, labor, or diificulty.

Having thus described my invention, I claim as new and desire to secure by Letters Patent In a cupelling-furnace, the combination of the cupel-hearth O,provided with a tap-channel, g, a lining of refractory material at Z Z,

JOHN JANTZE.

that several methods for tilting and mechanism for tipping the cupel, as de- 7 

